When it comes to evaluating their children, parents aren't known for objectivity. After all, everyone usually thinks their kids are above average in every way, even though that is statistically impossible. But it turns out, strangely, that many parents are not very good at telling when their kids are above average in the weight department. A new study has found that most mothers tend to think their overweight children are not as heavy as they actually are, and a fair number of mothers would fatten their kids up even more if they could.

The concern is that this skewed perception of children's weight and the tendency to equate chubbiness in toddlers with good health is contributing to childhood obesity. To get a picture of how mothers viewed their own children, the study interviewed 281 mothers recruited from two clinics in the Baltimore area that serve mostly low-income mothers. They made this choice because kids from low-income families are at the higher risk of ending up overweight or obese. The mothers' ages ranged between 18 and 48, and 71 percent of them were African-American. They were all shown a cartoon featuring the silhouettes of seven toddlers in a row, ranging from underweight to obese. The moms were asked to select the picture that most closely resembled their own kid. They were also told to pick the picture that they most wanted their child to look like.

The researchers used the actual height and weight of these mom's children to compare them to the images the mothers had chosen. In the end, nearly 70 percent of the moms did not accurately assess their own child's body size. Lead author Erin Hager, of the University of Maryland School of Medicine, explains,

Specifically, mothers of overweight toddlers consistently tended to chose a silhouette that was smaller than their child's true body size.

Moms who were overweight themselves were the least likely to opt for the correct silhouette. In terms of whether they wanted their toddlers' bodies to look different than they did, the moms of overweight kids actually tended to be satisfied with how their kids appeared. Mothers of underweight toddlers, on the other hand, were more likely to correctly assess their child's body size and to wish they looked different. Interestingly, four percent of mothers with overweight kids wanted them to be even heavier, and 21 percent of moms whose kids were at a healthy weight said they wished their kids weighed more.

So why, given that obesity affects 17 percent of children and teens and is such a major problem in this country, would parents be totally fine with having heavy kids and in some cases want their kids to be even heavier? Well, for one thing, there's a longstanding belief that a chubby toddler is the best kind of toddler. Says Hager,

A long time ago, it was O.K. to value a chubby baby when kids were underweight and we had potato famines and what not. It was a sign you're doing well for yourself. But that is not how it is today in the United States.

Ahh, yes, potato famines and what not. Those were the days. Now that we have a glut of potatoes and pretty much everything else imaginable, there's no reason to fatten kids up just in case of future starvation. But that image persists, and it's true that chubby baby cheeks are pretty irresistible, but there's a difference between having a healthy toddler with a little pudge and having one who's doomed to a life of obesity-related health problems.

A complicating factor in all of this is that mothers' ideas of what is normal have shifted because they see so many other overweight children and adults around them. In other words, they're not comparing their toddler's size to a theoretical ideal, they're comparing him or her to the other toddlers around, many of whom are overweight too. This misperception is fueled by the fact that pediatricians aren't direct enough about informing and educating parents. According to Hager, "Seventy-five percent of parents of overweight kids have never been told that by a pediatrician." So if no one ever tells you there's a problem with your child's weight and you're operating off the standard belief that it's good to fatten up babies, why wouldn't that be your goal? The concern of researchers, however, is that this impulse is what leads to kids being overfed and can shape their eating habits for the rest of their lives.